The field of the present invention is bracing hardware for use in building structures for utility piping.
Building codes, as well as competent construction practice, require the securing of fluid lines and other utilities to the structure of the building to brace such lines against damaging movement resulting from seismic disturbances. Sway braces have been designed for securing numerous types of fluid supply piping. An example of such secured piping is fire control water sprinkler distribution pipes. When sprinkler systems are used in buildings, it is required that the water distribution pipes be adequately braced, so that, in the event of an earthquake, the pipes will not unduly sway relative to adjacent portions of the building and separate or produce excessive leakage at the pipe joints.
Various types of sway brace structures have been developed for the foregoing purpose. Examples of such brace designs are to be found in U.S. Pat. Nos. 3,570,794; 4,697,770; 6,508,441; and 6,629,678. Further, a number of devices may be employed for mounting such bracing to a structure. Examples are found in U.S. Pat. Nos. 5,004,193; 5,007,603; 5,145,132; 6,334,285; 6,464,422; 6,629,678; 6,749,359; and 6,898,905. A design of a pipe clamp used with such systems is found in U.S. Pat. Publication No. 2005/0230569. The disclosures of the aforementioned patents and patent publication are incorporated herein by reference.
Pipe used for utility purposes in construction, such as for fire sprinkler systems, comes in certain sizes and materials. These specified pipe sizes have nominal outside diameters which vary within specific mill tolerances. Such nominal sizes and the associated mill tolerances can differ based on pipe material such as steel, cooper and plastic and on pipe nominal diameter. Hardware applied to such utility pipe of these various specified sizes is frequently designed specifically for a specified size and identified as such. The design of such hardware contemplates the nominal dimensions and, where necessary, the tolerances thereof. Thus, there can be a specific relationship and fit achieved by such hardware which is defined by the nominal dimensions within tolerance limits of any given specified utility pipe size for which the hardware is made.
Building construction frequently uses steel web joists. Such devices employ two beams. The beams are mutually parallel and spaced apart to create a large moment of inertia for the joist. Cord elements extend at angles between the two so the beams will act as one in bending. Each beam includes a set of two elongated angle elements, or angle iron members, which are also mutually parallel. The cord elements extend for anchoring to between the elongated angle elements which form a cord space to receive the elements. Each angle element includes two legs extending at a right angle to one another, a first leg which is parallel with the first leg of the other angle element to define the cord space and a second leg extending in the opposite direction from the second leg of the other angle element. The legs of this building structure define flanges which may be used to attach sway brace structures.
FIG. 1 illustrates a prior art sway brace assembly. The assembly includes a pipe clamp 10 to attach to a utility pipe 12. The clamp has a circumferential body with flanges 14 which are held toward one another by a bolt 16. A linking assembly is attached to the pipe clamp 10 by the bolt 16. The linking assembly includes a pipe 18 with brackets 20, 22 at the ends. The bracket 20 pivotally attaches to a building structure while the bracket 22 pivotally attaches to the pipe clamp 10. This device can be employed when a close connection between the pipe clamp 10 and the building structure is not required.
It is frequently desirable to mount the utility pipe as close as possible to the building structure. Use of a conventional plate clamp 24 with a conventional pipe clamp 26 pivotally mounted to it by a pivot mounting 28 has been proposed where a close positioning between the constrained pipe and the beam of the trust joist is of interest. However, the building structure is not predictably uniform and can create difficulties when the structure is askew with the utility pipe in a close fit environment.